Bug#775424: live-build: xorriso must be called with iso level 3 to support larger live systems

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

some theoretical background:

-iso-level 3 implies -iso-level 2 which allows file names with
32 characters rather than only 8+"."+3 characters. So if the
boot loader interprets ISO 9660 names rather than Rock Ridge
names, previously truncated names might become longer.

-iso-level 3 will not make any further difference towards the
default level 1 with data files smaller than 4 GiB. So when not
actually needed, it imposes no extra risk.

Files of 4 GiB or larger will be represented by multiple file
sections (aka extents). Modern Linux kernels have no problem
with that, when reading data files from the mounted ISO filesystem.
The BSDs and Solaris will show large files in various ill ways,
though.


Have a nice day :)

Thomas